MACULAR HOLE STUDY

The largest population-based study ever conducted to investigate the epidemiology of macular holes has identified risk factors that relate to age, gender, race and phakic status, reported Ferhina S Ali MD, MPH at the 2015 annual meeting of the Association for Research in Vision and Ophthalmology in Denver, USA.

Dr Ali, in collaboration with Jay Stewart MD of the University of California, San Francisco and Joshua Stein MD, MS of the University of Michigan, will follow up these findings with further analyses that may improve understanding of macular hole pathophysiology and prevention.

The retrospective longitudinal cohort analysis drew on insurance claims data from a large United States-managed care network for the years 2001 through to 2011. It identified nearly 2.5 million patients who met the inclusion/exclusion criteria. Eligible patients were at least 40 years old and had at least one visit to an eye provider while being enrolled in the plan for at least three years. Patients with diabetes, uveitis or prior diagnosis or vitrectomy were excluded.

During a mean follow-up of 2.6 years, 1,130 (0.05 per cent) patients developed a macular hole that required vitrectomy within 90 days of diagnosis. Multivariable analysis adjusting for sociodemographic factors and ocular and systemic comorbidities identified a 50 per cent increased risk of macular holes among women compared to men. In an age and gender interaction model, the risk of macular holes increased four per cent with each year of age among men, whereas among women it increased 53 per cent.

Asians had a 50 per cent increased risk of developing a macular hole compared with non-Hispanic whites, and individuals who were pseudophakic or aphakic had a two-fold higher risk than their phakic counterparts.
The risk associated with a history of ocular trauma approached, but did not reach,
statistical significance.

“We know that vitreomacular adhesion and vitreomacular traction (VMT) play a role in macular hole development. Now, as we move toward pharmacotherapeutics for VMT, it is important that we revisit our understanding of macular hole incidence and risk factors,” said Dr Ali, resident, Department of Ophthalmology, University of California, San Francisco, USA.

“Previous epidemiologic data in this area, from single institution and single region studies, have revealed our current understanding of macular hole incidence and risk factors. Our data, from a diverse group of patients throughout the United States, are consistent with earlier findings on macular hole incidence, and in showing a significantly increased risk of macular hole in women compared with men, and particularly among women in their perimenopausal years,” she added.

Commenting on the study methods, Dr Ali noted that the managed care network database used in the study afforded a large sample - it encompassed nearly 16 million patients who received any form of eye care - and it allows longitudinal follow-up.

“Our colleagues have previously validated use of these claims data to accurately estimate incident cases of other ocular pathologies, including nonexudative age-related macular degeneration and nonproliferative diabetic retinopathy,” she said.

“The consistency of our findings on macular holes with those of smaller studies lends reliability to use of these claims data for future investigation of questions relating to macular holes and to look for exposures that might modify risk.”

FUTURE DIRECTIONS

Dr Ali stated that previous studies attempting to understand the underlying aetiology for the increased incidence of macular holes in perimenopausal women have focused on a role of oestrogens, and how oestrogen might affect vitreoretinal dynamics.

“Now our group is planning to use the information from the managed care network database to investigate whether exposure to hormone replacement therapy may modify the risk of macular holes in older women,” she said.

Dr Ali acknowledged the potential for misclassification and miscoding of claims data, but she noted the requirement for macular holes to be linked to vitrectomy attempted to mitigate such errors.

“The vitrectomy criterion also narrows our cases of macular holes to those that were more likely to be visually significant,” she said.

Dr Ali also pointed out that, despite the strengths of the study’s population, its findings cannot necessarily be generalised to persons outside the health system examined or to the uninsured.

In addition, she observed that refractive error data could not be extracted, which would have been of interest to see if it might explain the increased risk noted among Asians.

Ferhina S Ali: alif@vision.ucsf.edu